A New Species of the Genus Pseudoparamenexenus (Phasmatodea: Lonchodidae: Necrosciinae) and Its Phylogenetic Relationships

We describe a new stick insect species, Pseudoparamenexenus beiliuensis sp. nov., by an integrated approach using morphological and molecular data. The mitochondrial genomes of this new species and Pseudoparamenexenus yangi collected from Jianfengling, Hainan, China, were fully sequenced and annotated. Both mitogenomes contained the standard metazoan gene set arranged in the ancestral phasmid order, with ATP8 showing the highest evolutionary rate, and COX1 the strongest purifying selection. Phylogenetic analyses were conducted based on 13 protein-coding genes, revealing the two species form a well-supported sister-group relationship. The systematic position of the genus Pseudoparamenexenus was resolved as follows: ((Pseudoparamenexenus beiliuensis sp. nov. + Pseudoparamenexenus yangi) + (Neohirasea stephanus + (Neohirasea japonica + Neohirasea hongkongensis))) + ((Pachyscia longicauda + Acanthophasma brevicercum) + ((Sinophasma brevipenne + Micadina phluctainoides) + (Micadina brevioperculina + Micadina brachyptera))). The discovery of this species not only advances our understanding of the genus Pseudoparamenexenus but also addresses knowledge gaps concerning the diversity of stick insects.